Smoke Flamer (#6146)

# About the pull request
adds a new flamer fuel tank that turns any reagent inside into chemsmoke
when fired
fuel tank obtainable from army lathe (OT lathe)
only 1 reagent allowed inside the tank so its not overpowered
cannot be used with the nozzle
the smoke will always have a set ammount of units in it (somewhat high)
so that it works effectively with the on_touch reactions

# Explain why it's good for the game
more flamer fuel variety
new ways to apply anti-xeno chems

# Testing Photographs and Procedure

https://www.youtube.com/watch?v=ePTXqXiK330

# Changelog
:cl:
add: Adds in a new incinerator smoke tank that turns any reagent inside
it into chemsmoke when fired.
/:cl:

---------

Co-authored-by: Drathek <[email protected]>

code/game/machinery/autolathe_datums.dm

@@ -331,6 +331,11 @@
 	path = /obj/item/ammo_magazine/flamer_tank/custom/large
 	category = AUTOLATHE_CATEGORY_EXPLOSIVES
 
+/datum/autolathe/recipe/armylathe/smoke_tank
+	name = "Custom M240A1 Smoke Tank"
+	path = /obj/item/ammo_magazine/flamer_tank/smoke
+	category = AUTOLATHE_CATEGORY_EXPLOSIVES
+
 //Medilathe recipes
 /datum/autolathe/recipe/medilathe
 	category = AUTOLATHE_CATEGORY_MEDICAL

code/modules/projectiles/gun_attachables.dm

@@ -3223,6 +3223,10 @@ Defined in conflicts.dm of the #defines folder.
 		to_chat(user, SPAN_WARNING("This chemical will clog the nozzle!"))
 		return
 
+	if(istype(gun.current_mag, /obj/item/ammo_magazine/flamer_tank/smoke)) // you can't fire smoke like a projectile!
+		to_chat(user, SPAN_WARNING("[src] can't be used with this fuel tank!"))
+		return
+
 	gun.last_fired = world.time
 	gun.current_mag.reagents.remove_reagent(flamer_reagent.id, FLAME_REAGENT_USE_AMOUNT * fuel_per_projectile)
 

code/modules/projectiles/guns/flamer/flamer.dm

@@ -136,10 +136,13 @@
 		click_empty(user)
 	else
 		user.track_shot(initial(name))
-		if(current_mag.reagents.has_reagent("stablefoam"))
-			unleash_foam(target, user)
+		if(istype(current_mag, /obj/item/ammo_magazine/flamer_tank/smoke))
+			unleash_smoke(target, user)
 		else
-			unleash_flame(target, user)
+			if(current_mag.reagents.has_reagent("stablefoam"))
+				unleash_foam(target, user)
+			else
+				unleash_flame(target, user)
 		return AUTOFIRE_CONTINUE
 	return NONE
 
@@ -229,6 +232,66 @@
 
 	new /obj/flamer_fire(to_fire, create_cause_data(initial(name), user), R, max_range, current_mag.reagents, flameshape, target, CALLBACK(src, PROC_REF(show_percentage), user), fuel_pressure, fire_type)
 
+/obj/item/weapon/gun/flamer/proc/unleash_smoke(atom/target, mob/living/user)
+	last_fired = world.time
+	if(!current_mag || !current_mag.reagents || !current_mag.reagents.reagent_list.len)
+		return
+
+	var/source_turf = get_turf(user)
+	var/smoke_range = 5 // the max range the smoke will travel
+	var/distance = 0 // the distance traveled
+	var/use_multiplier = 3 // if you want to increase the ammount of units drained from the tank
+	var/units_in_smoke = 35 // the smoke overlaps a little so this much is probably already good
+
+	var/datum/reagent/chemical = current_mag.reagents.reagent_list[1]
+	var/datum/reagents/to_disperse = new() // this is the chemholder that will be used by the chemsmoke
+	to_disperse.add_reagent(chemical.id, units_in_smoke)
+	to_disperse.my_atom = src
+
+	var/turf/turfs[] = get_line(user, target, FALSE)
+	var/turf/first_turf = turfs[1]
+	var/turf/second_turf = turfs[2]
+	var/ammount_required = (min(turfs.len, smoke_range) * use_multiplier) // the ammount of units that this click requires
+	for(var/turf/turf in turfs)
+
+		if(chemical.volume < ammount_required)
+			smoke_range = round(chemical.volume / use_multiplier)
+
+		if(distance >= smoke_range)
+			break
+
+		if(turf.density)
+			break
+		else
+			var/obj/effect/particle_effect/smoke/chem/checker = new()
+			var/atom/blocked = LinkBlocked(checker, source_turf, turf)
+			if(blocked)
+				break
+
+		playsound(turf, 'sound/effects/smoke.ogg', 25, 1)
+		if(turf != first_turf && turf != second_turf) // we skip the first tile and make it small on the second so the smoke doesn't touch the user
+			var/datum/effect_system/smoke_spread/chem/smoke = new()
+			smoke.set_up(to_disperse, 5, loca = turf)
+			smoke.start()
+		if(turf == second_turf)
+			var/datum/effect_system/smoke_spread/chem/smoke = new()
+			smoke.set_up(to_disperse, 1, loca = turf)
+			smoke.start()
+		sleep(2)
+
+		distance++
+
+	var/ammount_used = distance * use_multiplier // the actual ammount of units that we used
+
+	chemical.volume = max(chemical.volume - ammount_used, 0)
+
+	current_mag.reagents.total_volume = chemical.volume // this is needed for show_percentage to work
+
+	if(chemical.volume < use_multiplier) // there aren't enough units left for a single tile of smoke, empty the tank
+		current_mag.reagents.clear_reagents()
+
+	show_percentage(user)
+
 /obj/item/weapon/gun/flamer/proc/unleash_foam(atom/target, mob/living/user)
 	last_fired = world.time
 	if(!current_mag || !current_mag.reagents || !current_mag.reagents.reagent_list.len)

code/modules/projectiles/magazines/flamer.dm

@@ -90,7 +90,7 @@
 		to_chat(user, SPAN_WARNING("You can't mix fuel mixtures!"))
 		return
 
-	if(!to_add.intensityfire && to_add.id != "stablefoam")
+	if(!to_add.intensityfire && to_add.id != "stablefoam" && !istype(src, /obj/item/ammo_magazine/flamer_tank/smoke))
 		to_chat(user, SPAN_WARNING("This chemical is not potent enough to be used in a flamethrower!"))
 		return
 
@@ -236,3 +236,9 @@
 	max_intensity = 60
 	max_range = 8
 	max_duration = 50
+
+/obj/item/ammo_magazine/flamer_tank/smoke
+	name = "Custom incinerator smoke tank"
+	desc = "A tank holding powdered smoke that expands when exposed to an open flame and carries any chemicals along with it."
+	matter = list("metal" = 3750)
+	flamer_chem = null